Knife-adjusting means for rotary shears



Mar a Nov. 24, 1953 J. R. LANE 2,660,242

KNIFE-ADJUSTING MEANS FOR ROTARY SHEARS Filed Dec. 12, 1951 20a. 1: 25 24a, 24 23 F I I: m -/7.

17a INVENTOR 5 MOI/1V2. AAA/E Patented Nov. 24, 1953 KNIFE-ADJUSTING MEANS FOR ROTARY SHEARS John, R.- Lane, ,Pitt'sburg; Cafifi, assignor to" United States Steel Corporation, a corporation Application-December 12, 1951, SerialNm 261,201.

7" Claims. 1 This invention relates toflying. shearsr of the rotary-cylinder type. and-in particular, to means for adjusting the knives. mounted on: the cylinders..

For satisfactory shearingthe knives of rotary shears must be. accurately adjusted. to assure proper cooperation of. the knives on thetwo cy1inders between which the material to be sheared. passes. This is rendered difficult .by the facts that the knives must be rigidly clamped during operation against the possibility of the slightest slippage yet. must be quickly demountable for regrinding and replacement. Shims have been used for adjustment heretofore but have obvious disadvantages.

I have invented a knife-adjusting means for rotary shears capableof effecting minute changes in the position of the knivesand positively holding them inadjusted position until securely clamped, prior to-starting the shear in operation. In a preferred embodiment, I provide a wedge bar slidable axially in a hole in the shear cylinder parallel to the axis thereof. The bar has wed ing surfaces spaced therealong. Studs engaging these surfaces abut the inner edge of a shear knife lying in a longitudinal slot in the circumference of the shear cylinder. The bar is threaded at one end and is adjusted axially by a nut in the form of a worm cylinder. A shaft disposed generally radially in the shear cylinder has a worm thereon for coaction with the worm cylinder whereby very fine adjustments of the knife position may be effected.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accom panying drawings illustrating the present preferred embodiment. In the drawings,

Figure 1 is a partial transverse section taken through a shear cylinder having the invention incorporated therein;

Figure 2 is a partial longitudinal section taken along the line 11-11 of Figure l; and

Figure 3 is a portion of Figure 2 to enlarged scale.

Referring now in detail to the drawings, a shear cylinder including a body II and trunnions l2, has a longitudinal slot 13 in the periphery thereof adapted to accommodate a knife I4 and a clamping bar l5 lying alongside the latter in the slot. By means of the trunnions, cylinder ID is journaled in bearings (not shown) for cooperation with a similar companion cylinder disposed parallel and adjacent thereto. The sides of the slot l3 converge inwardly and bar I5 has .2: a cross-section taperingcorrespondingly so that. when it is drawn inwardly by screws 1'6. threaded into the cylinder I0, the. bar clamps. the knife between itself and one side of. slot l3.

My improved knif'eradjusting and. positioning means includes abar. ll slidable in a bore l8 extending inwardly from one. end. of. the cylinder and parallel. to the axis. thereof. The. bar is. held against. rotation by a. key Fla and has. inclinedor wedging. surfaces lfi'jspaced therealong. Studs 20 slidabl'e in radial holes. 2.! spaced along. the cylinder and intersecting, bore l8; ride on these surfaces and, at their outer ends,v abutthe imier edge of knife I l. The studsare. held against rotation by keys 20a. By virtuecf the construction described, if screws It are. slightly backed off, longitudinal movement of. bar IT to the right as viewed in Figures 2 and 3 will cause knife 14' to be forced outwardly and movementof the bar to the left will. permit the knife. to. sink deeper into the slot.

Bar I"! has a screw 22 extending axially from one end thereof. Bore I8 is counterbored at the end adjacent screw 22 as shown at 23. A cylindrical nut 25 is threaded on the screw and is rotatable in the counterbore. It has worm-wheel teeth 24a machined around the exterior thereof. A bushing or plug 25 screwed in the end of hole I8 holds nut 24 in place in the counterbore. A thrust Washer 25a between the nut 24 and plug 25 prevents substantial torque from being appliied to the plug by friction on rotation of the nu To provide for rotation of nut 24, a hole 26 extending generally radially into cylinder in and intersecting hole l8 in the region of nut 24, has a shaft 21 therein including a worm 27a thereon meshing with the teeth on nut 24. A spacer sleeve 28 inserted in hole 26 surrounds the portion of shaft 27 outwardly of worm 21a and is held in place by a bushing 29 screwed into the outer end of the hole. The shaft 2! has a slot or socket in its outer end whereby it may be turned manually by using a suitable tool, thus causing rotation of the nut. This construction, of course, provides a very fine adjustment of the knife and positive actuation thereof to the desired height above the surface of the shear cylinder. Whenever adjustment of the knife is needed, it is only necessary to loosen screws l5 and turn shaft 21. When the desired adjustment is efiected by rotation of nut 24 and longitudinal movement of bar H, the screws [6 may be retightened.

It will be apparent that the knife-adjusting means of my invention has numerous advantages. In the first place, the mechanism is simple and rugged and easy to operate without a high degree of skill. It is not necessary to remove the knife to make the adjustment as it is when using shims, and the amount of adjustment may be made as small as desired, not being limited to definite steps as with shims. The height of the cutting edge of the knife above the periphery of the cylinder can be measured by an indicator gauge as the adjustment is being made, thus assuring greater accuracy. The spaced studs provide a more solid backing for the knife than shims, since any dirt or foreign matter will collect in the knife slot between the studs instead of between the studs and the knife.

Although I have disclosed herein but a preferred embodiment of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

' 1. In a rotary-shear cylinder having a longitudinal slot in the periphery thereof adapted to receive a knife, the combination therewith of a wedge bar extending into said cylinder inwardly of said knife and slidable axially therein, a screw extending axially from one end of said bar, a worm cylinder threaded on said screw, a worm shaft extending generally radially of the shear cylinder and having a worm thereon meshing with said worm cylinder for turning said worm cylinder and sliding said bar, and means effective on sliding movement of the bar for moving said knife outwardly in said slot.

2. The apparatus defined by claim 1 characterized by said last-mentioned means including inclined surfaces spaced along said bar and studs riding on said surfaces and abutting said knife.

3. In a rotary shear, the combination with a cylinder having a longitudinal slot in the surface thereof and a knife disposed therein, said cylinder having a hole extending inwardly from one end parallel to its axis and between said axis and said slot, of a wedge bar slidable in said hole, a screw coaxial with said bar, a worm cylinder threaded on said screw for adjusting the bar longitudinally, a worm operable from the exterior of the shear cylinder meshing with said worm cylinder and means effective on longitudinal movement of the bar in one direction to force said knife outwardly in said slot.

4. The apparatus defined by claim 3 characterized by said shear cylinder having a generally radial hole therein intersecting said first-mentioned hole, and a worm shaft in said radial hole, said worm being formed on said shaft.

5. The apparatus defined by claim 3 characterized by said hole having a counterbore at its outer end to accommodate said nut and means for retaining said nut in said counterbore.

6. The apparatus defined by claim 5 characterized by said retaining means being a plug screwed into said counterbore.

'7. The apparatus defined by claim 3 characterized by said last-mentioned means including inclined surfaces on said bar and studs riding on said surfaces and extending therefrom to said knife.

JOHN R. LANE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 244,979 Clause Aug. 2, 1-881 562,985 Taylor June 30, 1896 565,186 Taylor Aug. 4, 1896 886,332 Sibley Apr. 28, 19-68 1,476,155 Dexter Dec. 4, 1923 1,751,562 Stinger Mar. 25, 1930 

